1. Field of the Invention
This invention relates generally to orthopedic surgery, and more particularly to tools intended to provide smooth faces on bone surfaces to facilitate installation and anchoring of artificial joint implants and the like.
2. Description of the Prior Art
A U.S. Pat. No. 2,785,673 issued Mar. 19, 1957 to Anderson discloses a femoral prosthesis and method of installation of it. One of the steps in the procedure is to employ a facer tool 35 which has cutting blades 35' on its lower face as shown on FIG. 8. This tool is rotated on stem 34 to cut a flat face 37 at the upper end of the femur 22 on which the head 39 (FIG. 6) of the prosthesis can be seated.
A more recent U.S. Pat. No. 4,467,801 issued Aug. 28, 1984 to Whiteside shows a similar, hand operated plateau planer having an abraded surface 31 with a plurality of cutting ridges 32 (FIGS. 3 and 4) to provide a flat surface 62 on the tibia to receive and support a tibial prosthesis.
When such planing tools are used by hand, the procedure is comparatively slow and unsatisfactory. When such tools are powered, the tool performance is not particularly satisfactory. For example, there is an accumulation of bone cuttings which inhibit good cutting action. The tendency of the tool operator is to apply more pressure. This, combined with the additional time required, generates heat at the bone surface being treated, which can result in thermal damage to the bone. It can also cause bone perimeter damage, more particularly fragmentation at the edge of the surface. It is an object of the present invention to improve cutting efficiency for bone facing operations to reduce time and effort and avoid a tendency toward bone damage in such operations.